As generally known in the art, next-generation communication systems have evolved in the form of a communication system capable of transmitting/receiving data at high speed while ensuring the mobility of a plurality of mobile stations. Also, next-generation communication systems can provide services with varying quality of service (QoS) levels.
In recent years, research has been actively pursued to develop a next-generation communication system for providing users with high-capacity services with various QoS levels as well as high data transfer rate. In such a next-generation communication system, cells with a very small radius must be provided in order to enable high-speed communications and accommodate a large amount of calls. However, when very small cells are provided in a next-generation communication system, it may be impossible to implement the system in the current wireless network design scheme that corresponds to a centralized design scheme. In other words, the next-generation communication system is implemented in such a manner as to be controlled in a decentralized manner, and requires a wireless network design scheme capable of actively coping with environmental changes, such as the addition of a new base station (BS), and the like. Thus, a self-configurable wireless network architecture is required for the next-generation communication system. Here, the self-configurable wireless network refers to a wireless network that can provide communication services through autonomous and decentralized configurations without the control of a central system.
In order to implement the self-configurable wireless network in a next-generation communication system, schemes applied in an ad hoc network, which enables communications between respective devices, must be employed in the next-generation communication system. A typical example thereof is a cellular network using a multi-hop relay scheme, in which a multi-hop relay scheme applied in an ad-hoc network is employed in a cellular network system including a fixed base station (BS).
In particular, next-generation communications are actively considering using the multi-hop relay scheme for increasing system capacity and extending service coverage. Hereinafter, how to increase system capacity and extend service coverage in a communication system using a multi-hop scheme (hereinafter referred to as “multi-hop communication system”) will be discussed. First of all, an increase in system capacity is achieved as follows: when channel conditions between a BS and an MS in a multi-hop communication system are relatively poor, a relay station (RS) located between the BS and the MS relays data transmitted and received between the BS and the MS. Thus, the MS can increase data capacity by transmitting and receiving data over a channel that has better channel conditions from among the BS and the RS, which results in an increase in system capacity.
Next, an extension of service coverage is achieved as follows: in a multi-hop communication system, an RS relays data, which has been received from a BS, to an MS located within a cell region, or relays data, which has been received from an MS, to a BS.
However, there has not been concretely proposed an efficient data transmission/reception procedure between a BS and an RS and an MS when the same data is transmitted to a plurality of mobile stations in multi-hop communication system as described above.